The ability to produce leaner animals would have a significant impact on meat production. Several compounds are known to depress fat deposition in warm-blooded animals. However, none of those compounds have been commercialized for use in animals.
Accordingly, there is ongoing research to discover new methods for producing leaner animals.
Certain alpha-2 adrenergic receptor antagonists are known to possess lipolytic activity in vivo (see, for example, J. Galitzky, et al, European Journal of Clinical Investigation, 18, pages 587-594 (1988), B. Richelsen, European Journal of Clinical Investigation, 16, pages 302-309 (1986) and T. Ng, Comp. Biochem. Physiol., 82C, pages 463-466 (1985)). However, H. Mersmann in Comp. Biochem. Physiol., 79C, pages 165-170 (1984) discloses that several .alpha.-adrenergic antagonists do not enhance basal or stimulated lipolysis in vitro. And L. Coutinho, et al, in Comp. Biochem. Physiol., 105A, pages 333-339 (1993) disclose that the .alpha.-adrenergic antagonist yohimbine has no effect on lipolysis in adipocytes isolated from castrated pigs.
In view of those publications, it is not clear what effect .alpha.-adrenergic antagonists have on lipolysis. What is clear, however, is that none of those publications describe a method for producing leaner animals.
GB 999,394 describes animal feed and drink preparations which contain certain 17-methoxy-18-alkoxy-yohimbine derivatives However, that patent does not describe a method for producing leaner animals.
It is, therefore, an object of the present invention to provide a method for increasing lean meat, improving the lean meat to fat ratio and improving amino acid utilization in warm-blooded animals.
It is also an object of the present invention to provide animal feed and animal feed supplement compositions which increase lean meat, improve the lean meat to fat ratio and improve amino acid utilization in warm-blooded animals.
Those and other objects and features of the present invention will become more apparent from the detailed description thereof set forth below.